Method and Device for In-Line Injection of Flocculent Agent into a Fluid Flow of Mature Fine Tailings

ABSTRACT

A method and device for in-line injecting of flocculent agent into a fluid flow of mature fine tailings (MFT). The method includes the steps of: a) providing a fluid flow of mature fine tailings to be treated along a given channel fluidly connected to the pipeline; b) providing a source of flocculating agent; and c) introducing flocculating agent inside the fluid flow of mature fine tailings via a plurality of injection outlets for injecting the flocculating agent into the fluid flow in a dispersed manner so as to increase an exposed surface area of the injected flocculating agent and thus increase a corresponding reaction with the mature fine tailings, for an improved flocculation of said mature fine tailings, and/or other desired end results. Also disclosed is a kit with corresponding components for assembling the in-line injection device to be connected in-line with the pipeline carrying the mature fine tailings to be treated.

FIELD OF THE INVENTION

The present invention relates to an injection method. More particularly,the present invention relates to a method and to a corresponding devicefor in-line injection of flocculent agent into a fluid flow of maturefine tailings.

BACKGROUND OF THE INVENTION

Oil sand fine tailings have become a technical, operational,environmental, economic and public policy issue.

Oil sand tailings are generated from hydrocarbon extraction processoperations that separate the valuable hydrocarbons from oil sand ore.All commercial hydrocarbon extraction processes use variations of theClark Hot Water Process in which water is added to the oil sands toenable the separation of the valuable hydrocarbon fraction from the oilsand minerals. The process water also acts as a carrier fluid for themineral fraction. Once the hydrocarbon fraction is recovered, theresidual water, unrecovered hydrocarbons and minerals are generallyreferred to as “tailings”.

The oil sand industry has adopted a convention with respect to mineralparticle sizing. Mineral fractions with a particle diameter greater than44 microns are referred to as “sand”. Mineral fractions with a particlediameter less than 44 microns are referred to as “fines”. Mineralfractions with a particle diameter less than 2 microns are generallyreferred to as “clay”, but in some instances “clay” may refer to theactual particle mineralogy. The relationship between sand and fines intailings reflects the variation in the oil sand ore make-up, thechemistry of the process water and the extraction process.

Conventionally, tailings are transported to a deposition site generallyreferred to as a “tailings pond” located close to the oil sands miningand extraction facilities to facilitate pipeline transportation,discharging and management of the tailings. Due to the scale ofoperations, oil sand tailings ponds cover vast tracts of land and mustbe constructed and managed in accordance with regulations. Themanagement of pond location, filling, level control and reclamation is acomplex undertaking given the geographical, technical, regulatory andeconomic constraints of oil sands operations.

Each tailings pond is contained within a dyke structure generallyconstructed by placing the sand fraction of the tailings within cells oron beaches. The process water, unrecovered hydrocarbons, together withsand and fine minerals not trapped in the dyke structure flow into thetailings pond. Tailings streams initially discharged into the ponds mayhave fairly low densities and solids contents, for instance around0.5-10 wt %.

In the tailings pond, the process water, unrecovered hydrocarbons andminerals settle naturally to form different strata. The upper stratum isprimarily water that may be recycled as process water to the extractionprocess. The lower stratum contains settled residual hydrocarbon andminerals which are predominately fines. This lower stratum is oftenreferred to as “mature fine tailings” (MFT). Mature fine tailings havevery slow consolidation rates and represent a major challenge totailings management in the oil sands industry.

The composition of mature fine tailings is highly variable. Near the topof the stratum the mineral content is about 10 wt % and through timeconsolidates up to 50 wt % at the bottom of the stratum. Overall, maturefine tailings have an average mineral content of about 30 wt %. Whilefines are the dominant particle size fraction in the mineral content,the sand content may be 15 wt % of the solids and the clay content maybe up to 75 wt % of the solids, reflecting the oil sand ore andextraction process. Additional variation may result from the residualhydrocarbon which may be dispersed in the mineral or may segregate intomat layers of hydrocarbon. The mature fine tailings in a pond not onlyhas a wide variation of compositions distributed from top to bottom ofthe pond but there may also be pockets of different compositions atrandom locations throughout the pond.

Mature fine tailings behave as a fluid-like colloidal material. The factthat mature fine tailings behave as a fluid significantly limits optionsto reclaim tailings ponds. In addition, mature fine tailings do notbehave as a Newtonian fluid, which makes continuous commercial scaletreatments for dewatering the tailings all the more challenging. Withoutdewatering or solidifying the mature fine tailings, tailings ponds haveincreasing economic and environmental implications over time.

There are some methods that have been proposed for disposing of orreclaiming oil sand tailings by attempting to solidify or dewater maturefine tailings. If mature fine tailings can be sufficiently dewatered soas to convert the waste product into a reclaimed firm terrain, then manyof the problems associated with this material can be curtailed orcompletely avoided. As a general guideline target, achieving a solidscontent of 75 wt % for mature fine tailings is considered sufficiently“dried” for reclamation.

One known method for dewatering MFT involves a freeze-thaw approach.Several field trials were conducted at oil sands sites by depositing MFTinto small, shallow pits that were allowed to freeze over the winter andundergo thawing and evaporative dewatering the following summer. Scaleup of such a method would require enormous surface areas and would behighly dependent on weather and season. Furthermore, other restrictionsof this setup were the collection of release water and precipitation onthe surface of the MFT which discounted the efficacy of the evaporativedrying mechanism.

Some other known methods have attempted to treat MFT with the additionof a chemical to create a thickened paste that will solidify oreventually dewater.

One such method, referred to as “consolidated tailings” (CT), involvescombining mature fine tailings with sand and gypsum. A typicalconsolidated tailings mixture is about 60 wt % mineral (balance isprocess water) with a sand to fines ratio of about 4 to 1, and about 600to 1000 ppm of gypsum. This combination can result in a non-segregatingmixture when deposited into the tailings ponds for consolidation.However, the CT method has a number of drawbacks. It relies oncontinuous extraction operations for a supply of sand, gypsum andprocess water. The blend must be tightly controlled. Also, whenconsolidated tailings mixtures are less than 60 wt % mineral, thematerial segregates with a portion of the fines returned to the pond forreprocessing when settled as mature fine tailings. Furthermore, thegeotechnical strength of the deposited consolidated tailings requirescontainment dykes and, therefore, the sand required in CT competes withsand used for dyke construction until extraction operations cease.Without sand, the CT method cannot treat mature fine tailings.

Another method conducted at lab-scale sought to dilute MFT preferably to10 wt % solids before adding Percol LT27A or 156. Though the morediluted MFT showed faster settling rates and resulted in a thickenedpaste, this dilution-dependent small batch method could not achieve therequired dewatering results for reclamation of mature fine tailings.

Some other methods have attempted to use polymers or other chemicals tohelp dewater MFT. However, these methods have encountered variousproblems and have been unable to achieve reliable results. Whengenerally considering methods comprising chemical addition followed bytailings deposition for dewatering, there are a number of importantfactors that should not be overlooked.

Of course, one factor is the nature, properties and effects of the addedchemicals. The chemicals that have shown promise up to now have beendependent on oil sand extraction by-products, effective only atlab-scale or within narrow process operating windows, or unable toproperly and reliably mix, react or be transported with tailings. Someadded chemicals have enabled thickening of the tailings with no changein solids content by entrapping water within the material, which limitsthe water recovery options from the deposited material. Some chemicaladditives such as gypsum and hydrated lime have generated water runoffthat can adversely impact the process water reused in the extractionprocesses or dried tailings with a high salt content that is unsuitablefor reclamation.

Another factor is the chemical addition technique. Known techniques ofadding sand or chemicals often involve blending materials in a tank orthickener apparatus. Such known techniques have several disadvantagesincluding requiring a controlled, homogeneous mixing of the additive ina stream with varying composition and flows which results ininefficiency and restricts operational flexibility. Some chemicaladditives also have a certain degree of fragility, changeability orreactivity that requires special care in their application.

Another factor is that many chemical additives can be very viscous andmay exhibit non-Newtonian fluid behaviour. Several known techniques relyon dilution so that the combined fluid can be approximated as aNewtonian fluid with respect to mixing and hydraulic processes. Maturefine tailings, however, particularly at high mineral or clayconcentrations, demonstrates non-Newtonian fluid behaviour.Consequently, even though a chemical additive may show promise as adewatering agent in the lab or small scale batch trials, it is difficultto repeat performance in an up-scaled or commercial facility. Thisproblem was demonstrated when attempting to inject a viscous polymeradditive into a pipe carrying MFT. The main MFT pipeline was intersectedby a smaller side branch pipe for injecting the polymer additive. ForNewtonian fluids, one would expect this arrangement to allow highturbulence to aid mixing. However, for the two non-Newtonian fluids, thefield performance with this mixing arrangement was inconsistent andinadequate. There are various reasons why such mixing arrangementsencounter problems. When the additive is injected in such a way, it mayhave a tendency to congregate at the top or bottom of the MFT streamdepending on its density relative to MFT and the injection directionrelative to the flow direction. For non-Newtonian fluids, such asBingham fluids, the fluid essentially flows as a plug down the pipe withlow internal turbulence in the region of the plug. Also, when thechemical additive reacts quickly with the MFT, a thin reacted region mayform on the outside of the additive plug thus separating unreactedchemical additive and unreacted MFT.

Inadequate mixing can greatly decrease the efficiency of the chemicaladditive and even short-circuit the entire dewatering process.Inadequate mixing also results in inefficient use of the chemicaladditives, some of which remain unmixed and unreacted and cannot berecovered. Known techniques have several disadvantages including theinability to achieve a controlled, reliable or adequate mixing of thechemical additive as well as poor efficiency and flexibility of theprocess.

Still another factor is the technique of handling the oil sand tailingsafter chemical addition. If oil sand tailings are not handled properly,dewatering may be decreased or altogether prevented. In some pasttrials, handling was not managed or controlled and resulted inunreliable dewatering performance. Some techniques such as in CIBA'sCanadian patent application No. 2,512,324 (SCHAFFER et al.) haveattempted to simply inject the chemical into the pipeline without amethodology to reliably adapt to changing oil sand tailingscompositions, flow rates, hydraulic properties or the nature ofparticular chemical additive. Relying solely on this ignores the complexnature of mixing and treating oil sand tailings and significantlyhampers the flexibility and reliability of the system. When the chemicaladdition and subsequent handling have been approached in such anuncontrolled, trial-and-error fashion, the dewatering performance hasbeen unachievable.

Yet another factor is the technique of handling or treating the MFTprior to chemical addition. MFT is drawn up by pumps or dredgingequipment from tailings ponds and preferably sent via pipeline to thedewatering treatment area. The tailings ponds, however, may contain avariety of materials that could disrupt the MFT dewatering process. Forinstance, in the raw MFT there may be mats of bitumen, particularly inthe cold winter months. There may also be other extraneous debris suchas pieces of wood, glass, plastic, metal or natural organic materialthat can be entrained with the MFT as it is taken from the pond. Suchunwanted materials can interfere with the MFT process equipment andchemistry.

Given the significant inventory and ongoing production of MFT at oilsands operations, there is a need for techniques and advances that canenable MFT drying for conversion into reclaimable landscapes.

Known to the applicant are the following publications and patentdocuments, namely: OWEN, A. T. et al. “Using turbulent pipe flow tostudy the factors affecting polymer-bridging flocculation of mineralsystems”, International Journal of Mineral Processing, Vol. 87, Issues3-4, Jul. 2, 2008; VRALE et al., “Rapid Mixing in Water,” Jour. AWWA,January, 1971; WO 2002/079099 A1 (BRANNING, L.); WO 2009/009887 A1(BOZAK, R. et al.); and U.S. Pat. No. 5,839,828 (GLANVILLE, R.).

However, none of these prior art documents seem to teach, illustrate oreven suggest a solution for inefficient injection and mixing of liquidand polymer with mature fine tailings (MFT) which typically leave unusedpolymer in the drying cell area. This is particularly disadvantageous inthat it is both expensive and adversely affects the process. Therefore,it would be very useful to provide a new method or a correspondingdevice for faster and more efficient mixing of a flocculent agent, suchas a liquid polymer for example, with mature fine tailings (MFT).Indeed, it would be very useful to provide a new method or device whichwould enable a lower polymer usage for the same quantity of MFT ascompared to an un-optimized design which is typical to most conventionalsystems being used. It would also be very useful to provide for a newdevice which would be of very low maintenance, and which could be easilyfabricated in-house.

Hence, in light of the aforementioned, there is a need for a new methodor device of treating MFT which would be able to overcome or at leastminimize some of the above-discussed prior art concerns.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a device, which byvirtue of its design and components, satisfies some of theabove-mentioned needs and is thus an improvement over other relateddevices and/or methods known in the prior art.

In accordance with the present invention, the above object is achieved,as will be easily understood, with a device such as the one brieflydescribed herein, and such as the one exemplified in the accompanyingdrawings. Preferably, the device is an “add-on” to a pipeline carryingmature fine tailings (MFT), in the form of an injection device, intendedto be connected “in-line” with the pipeline.

More particularly, the present invention relates to an injection devicefor inline-injection of flocculating agent into a fluid flow of apipeline of mature fine tailings in order to promote flocculation ofsaid mature fine tailings, the injection device comprising:

-   -   a main inlet for receiving the fluid flow;    -   a main channel along which the fluid flow entering the inlet is        allowed to travel;    -   a main outlet for releasing the fluid flow; and    -   a complementary conduit, disposed co-annularly with respect to        the main channel, and configured for receiving flocculating        agent from a feed inlet different from the main inlet, the        complementary conduit having a plurality of injection outlets        disposed co-annularly about the main outlet for injecting        flocculating agent into the fluid flow exiting the main outlet,        the injection outlets being shaped and sized, and each having an        orifice substantially smaller than that of the feed inlet so as        to increase dispersion of the flocculating agent about the main        outlet in order to improve mixing of the fluid flow with said        flocculating agent via an increased exposed surface area of the        flocculating agent.

According to a preferred embodiment, the present invention also relatesto an injection device for use with a lateral pipe fitting of a pipelineof mature fine tailings, the lateral pipe fitting having a substantiallyy-joint arrangement including a main line along which a fluid flow ofmature fine tailings is intended to travel, and a corresponding branchline, the injection device comprising:

-   -   an abutment flange for abutting against a distal end of the        branch line;    -   a supporting body projecting from the abutment flange inwardly        towards the main line, the supporting body having an internal        conduit for conveying flocculent agent to be introduced into the        fluid flow via a corresponding distal extremity intersecting        said fluid flow of mature fine tailings; and    -   a plurality of injection outlets provided on the distal        extremity of the supporting body, and through which flocculent        agent is injected, the injection outlets being shaped and sized,        and each having an orifice substantially smaller than that of        the internal conduit so as to increase dispersion of the        flocculating agent about the injection outlets in order to        improve mixing of the fluid flow with said flocculating agent        via an increased exposed surface area of the flocculating agent        provided by the plurality of injection outlets.

According to another aspect of the present invention, there is alsoprovided a kit with components for assembling the above-mentionedinjection device.

Indeed, according to a preferred embodiment, the present inventionrelates to a kit for assembling an injection device for inline-injectionof flocculating agent into a fluid flow of a pipeline of mature finetailings in order to promote flocculation of said mature fine tailings,the kit comprising:

-   -   a tee joint having first, second and third sections, each        section being provided with a corresponding orifice being        fluidly connected to each other;    -   a first flange mountable about the first section of the tee        joint, said first flange being configured for mounting the        assembled injection device onto a first section of the pipeline;    -   a second flange mountable about the second section of the tee        joint, said second flange being configured for mounting the        assembled injection device onto a second section of the        pipeline;    -   a third flange mountable about the third section of the tee        joint, said third flange being configured for connecting the        assembled injection device to a source of flocculent agent;    -   a reducer mountable onto the first section of the tee joint so        as to be positioned inside the tee joint, the reducer having an        inlet and an outlet, the inlet of the reducer being        concentrically mountable about the orifice of the first section        of the tee joint, the cross-sectional area of the reducer being        reduced from its inlet to its outlet;    -   an inner pipe mountable onto the second section of the tee joint        so as to be positioned inside the tee joint, the inner pipe        having an inlet and an outlet, the inlet of the inner pipe being        connectable to the outlet of the reducer, the outlet of the        inner pipe being concentrically mountable about the orifice of        the second section of the tee joint, the inner pipe being        cooperable with the second section of the tee joint for defining        a plurality of injection outlets about the outlet of the inner        pipe so that flocculent agent coming from the third section of        the tee joint be injected in a dispersed manner through said        injection outlets and into a fluid flow of mature fine tailings        traveling through the reducer and the inner pipe.

According to yet another aspect of the present invention, there is alsoprovided a conversion kit including the above-mentioned device and/orcomponents.

According to yet another aspect of the present invention, there is alsoprovided a set of components for interchanging with components ofabove-mentioned device and/or kit.

According to yet another aspect of the present invention, there is alsoprovided a method for assembling components of the above-mentioned kitand/or set.

According to yet another aspect of the present invention, there is alsoprovided a method of using the above-mentioned device, kit, set and/orcomponents thereof.

According to yet another aspect of the present invention, there is alsoprovided a corresponding pipeline carrying mature fine tailings, thepipeline having been assembled with the above-mentioned device,conversion kit, set and/or method(s).

According to yet another aspect of the present invention, there is alsoprovided a method of manufacturing the above-mentioned device,corresponding kit and/or conversion set.

According to yet another aspect of the present invention, there is alsoprovided a method of introducing flocculent agent into a fluid flow ofmature fine tailings.

More particularly, the present invention also relates to a method ofin-line injection of flocculating agent into a pipeline of mature finetailings in order to promote flocculation of said mature fine tailings,the method comprising the steps of:

a) providing a fluid flow of mature fine tailings to be treated along agiven channel fluidly connected to the pipeline;

b) providing a source of flocculating agent; and

c) introducing flocculating agent inside the fluid flow of mature finetailings via a plurality of injection outlets for injecting theflocculating agent into the fluid flow in a dispersed manner so as toincrease an exposed surface area of the injected flocculating agent andthus increase a corresponding reaction with the mature fine tailings,for an improved flocculation of said mature fine tailings.

The objects, advantages and other features of the present invention willbecome more apparent upon reading of the following non-restrictivedescription of preferred embodiments thereof, given for the purpose ofexemplification only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an injection device according to apreferred embodiment of the present invention.

FIG. 2 is a perspective view of an inner component of the injectiondevice shown in FIG. 1.

FIG. 3 is a perspective view of an outer component of the injectiondevice shown in FIG. 1.

FIG. 4 is a front view of what is shown in FIG. 1.

FIG. 5 is a front view of what is shown in FIG. 2.

FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 4.

FIG. 7 is a schematic cross-sectional representation of a pipelinecarrying a fluid flow of mature fine tailings and being provided with aninjection device according to a preferred embodiment of the presentinvention.

FIG. 8 is a perspective view of an injection device according to anotherpreferred embodiment of the present invention.

FIG. 9 is a perspective view of an inner component of the injectiondevice shown in FIG. 8.

FIG. 10 is a perspective view of an outer component of the injectiondevice shown in FIG. 8.

FIG. 11 is a front view of what is shown in FIG. 8.

FIG. 12 is a front view of what is shown in FIG. 9.

FIG. 13 is a cross-sectional view taken along line XIII-XIII of FIG. 11.

FIG. 14 is a schematic cross-sectional representation of a pipelinecarrying a fluid flow of mature fine tailings and being provided with aninjection device according to another preferred embodiment of thepresent invention.

FIG. 15 is a perspective view of an injection device according to yetanother preferred embodiment of the present invention.

FIG. 16 is a perspective view of an inner component of the injectiondevice shown in FIG. 15.

FIG. 17 is a perspective view of an outer component of the injectiondevice shown in FIG. 15.

FIG. 18 is a front view of what is shown in FIG. 15.

FIG. 19 is a front view of what is shown in FIG. 16.

FIG. 20 is a cross-sectional view taken along line XX-XX of FIG. 18.

FIG. 21 is a schematic cross-sectional representation of a pipelinecarrying a fluid flow of mature fine tailings and being provided with aninjection device according to yet another preferred embodiment of thepresent invention.

FIG. 22 is a schematic representation of a pipeline intended to be usedwith at least one tailings pond and being provided with an injectiondevice according to another preferred embodiment of the presentinvention.

FIG. 23 is an enlarged schematic representation of a portion of what isshown in FIG. 22, including the injection device being connected in-linewith a pipeline of MFT and being connected to a source of flocculentagent.

FIG. 24 is a side view of an injection device according to yet anotherpreferred embodiment of the present invention.

FIG. 25 is a top view of what is shown in FIG. 24.

FIG. 26 is a front elevational view of what is shown in FIG. 24.

FIG. 27 is an exploded view of the components of the injection deviceshown in FIG. 24.

FIG. 28 is a side elevational view of a reducer according to a preferredembodiment of the present invention.

FIG. 29 is a front view of what is shown in FIG. 28.

FIG. 30 is a rear view of what is shown in FIG. 28.

FIG. 31 is a front plan view of a ring according to a preferredembodiment of the present invention.

FIG. 32 is a cross-sectional view taken along line XXXI I-XXXII of FIG.31.

FIG. 33 is a cross-sectional view taken along line XXXIII-XXXIII of theinjection device of FIG. 26.

FIG. 34 is an enlarged sectional view of a portion of what is shown inFIG. 33.

FIG. 35 is an enlarged sectional view of another portion of what isshown in FIG. 33.

FIG. 36 is an enlarged sectional view of another portion of what isshown in FIG. 33.

FIG. 37 is an enlarged sectional view of another portion of what isshown in FIG. 33.

FIG. 38 is an enlarged sectional view of a rear portion of what is shownin FIG. 33.

FIG. 39 is a branch fitting of a pipeline carrying mature fine tailingsand being provided with an injection device according to anotherpreferred embodiment of the present invention.

FIG. 40 is a branch fitting of a pipeline carrying mature fine tailingsand being provided with an injection device according to yet anotherpreferred embodiment of the present invention.

FIG. 41 is a side view of the injection device shown in FIG. 40.

FIG. 42 is an enlarged view of a distal front portion of the injectiondevice of FIG. 41.

FIG. 43 is a sectional view of a portion of what is shown in FIG. 42.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, the same numerical references refer tosimilar elements. The embodiments, geometrical configurations, materialsmentioned and/or dimensions shown in the figures are preferred, givenfor exemplification purposes only.

Moreover, although the present invention was primarily designed forinjecting flocculent agent, such as liquid polymer for example, into afluid flow of a pipeline carrying mature fine tailings (MFT) forexample, it may be used with other types of substance(s) and/orliquid(s), for other purposes, and in other fields, as apparent to aperson skilled in the art. For this reason, expressions such as“injecting”, “flocculent”, “agent”, “liquid, “polymer”, “pipeline”,“MFT”, etc. used herein should not be taken as to limit the scope of thepresent invention and includes all other kinds of pipelines, cylinders,items and/or applications with which the present invention could be usedand may be useful.

Moreover, in the context of the present invention, the expressions“device”, “kit”, “unit”, “apparatus”, “mechanism”, “assembly”, “spool”,“system”, “set” and any other equivalent expression and/or compound wordthereof known in the art will be used interchangeably. Furthermore, thesame applies for any other mutually equivalent and/or complementaryexpressions, such as “pipeline”, “cylinder”, “conduit”, “channel”, and“pipe”, as well as “additive”, “solution” and “agent” for example, oreven “flocculent”, “chemical” and “reactive”, as well as “co-annularly”,“co-axially”, “concentrically”, “conjointly” and “complementary”, asalso apparent to a person skilled in the art. The same can be said aboutother similar expressions such as “processing”, “mixing”, “treating”,solidifying”, “dewatering”, “flocculating” and “consolidating”, or even“outlet”, “orifice” and “hole”, as also apparent to a person skilled inthe art.

In addition, although the preferred embodiment of the present inventionas illustrated in the accompanying drawings comprises various componentsand although the preferred embodiment of the injecting device as shownconsists of certain geometrical configurations as explained andillustrated herein, not all of these components and geometries areessential to the invention and thus should not be taken in theirrestrictive sense, i.e. should not be taken as to limit the scope of thepresent invention. It is to be understood that other suitable componentsand cooperations thereinbetween, as well as other suitable geometricalconfigurations may be used for the injecting device and correspondingparts according to the present invention, as well as correspondingconversion kit or set, and/or resulting pipeline or circuit, as brieflyexplained herein, or as can be easily inferred herefrom, by a personskilled in the art, without departing from the scope of the presentinvention.

Broadly described, the present invention, as exemplified and shown inthe accompanying drawings, relates to an improved method of introducingflocculating agent into a fluid flow of a pipeline carrying mature finetailings in order to improve reaction of the flocculating agent withsaid mature fine tailings for an improved flocculating of the maturefine tailings, and/or corresponding resulting advantages, such asdewatering, for example. This new method of in-line injection offlocculating agent into a pipeline of mature fine tailings distinguishesitself from other known techniques in that the introduction offlocculating agent is done inside the fluid flow of mature fine tailingsvia a plurality of injection outlets for injecting the flocculatingagent into the fluid flow in a “dispersed manner”, so as to increase awetted perimeter and thus an exposed surface area of the injectedflocculating agent, in order to increase a corresponding reaction withthe mature fine tailings, for improved end results. The presentinvention also relates to a corresponding injection device for in-lineconnection with the pipeline carrying the mature fine tailings, and inorder to carry out the in-line injection method according to the presentinvention.

LIST OF NUMERICAL REFERENCES FOR SOME OF THE CORRESPONDING PREFERREDCOMPONENTS ILLUSTRATED IN THE ACCOMPANYING DRAWINGS

-   1. injection device-   3. flocculent agent-   5. fluid flow-   7. pipeline-   9. mature fine tailings-   11. main inlet-   13. main channel-   15. main outlet-   17. complementary conduit-   19. feed inlet-   21. injection outlet-   21 c. center point (of injection outlet 21)-   23. inner surface (of main conduit 13)-   25. connecting flange (of feed inlet 19)-   27. inner component-   29. cylinder-   31. first end (of cylinder 29)-   33. second end (of cylinder 29)-   35. ring (of cylinder 29)-   37. outer component-   39. sleeve-   41. first end (of sleeve 39)-   43. first flange (of first end 41)-   45. first section (of pipeline 7)-   47. second end (of sleeve 39)-   49. second flange (of first end 47)-   51. second section (of pipeline 7)-   53. peripheral surface (of sleeve 39)-   55. transitional segment-   57. interface segment-   59. main segment-   61. longitudinal axis (of fluid flow 5)-   63. tee joint-   65. first section (of tee joint 63)-   65 a. orifice (of first section 65)-   67. second section (of tee joint 63)-   67 a. orifice (of second section 67)-   69. third section (of tee joint 63)-   69 a. orifice (of third section 69)-   71. first flange-   73. second flange-   75. third flange-   77. reducer-   79. inlet (of reducer 77)-   81. outlet (of reducer 77)-   83. inner pipe-   85. inlet (of inner pipe 83)-   87. outlet (of inner pipe 83)-   89. outer pipe-   91. backing ring-   93. lap ring-   95. nut-   97 lateral pipe fitting-   99 main line (of lateral pipe fitting 97)-   101 branch line (of lateral pipe fitting 97)-   103 abutment flange-   105 distal end (of branch line 101)-   107 supporting body-   109 internal conduit-   111 distal extremity (of supporting body 107)-   113 stabilizer

As previously explained, and according to a preferred aspect of thepresent invention, there is provided an injection device (1) for in-lineinjection of flocculating agent (3) into a fluid flow (5) of a pipeline(7) of mature fine tailings (9) in order to promote reaction of theflocculent agent (3) with the mature fine tailings (9). As exemplifiedin the accompanying drawings, and more particularly in FIGS. 1-21, theinjection device (1) comprises a main inlet (11), a main channel (13), amain outlet (15), and a complementary conduit (17). The main inlet (11)is intended for receiving the fluid flow (5) of the pipeline (7)carrying mature fine tailings (9), and the main channel (13) is wherethe fluid flow (5) entering the inlet (11) is allowed to travel. Thefluid flow (5) circulating through the pipeline (7) and thus through theinjection device (1) which is connected in-line to the pipeline (7) isthen allowed to be released out from the main outlet (15) of theinjection device (1). An innovative aspect of the injection device (1)resides namely in its complementary conduit (17), which, as betterexemplified in FIGS. 6, 13 and 20, is preferably disposed co-annularly(or co-axially, conjointly, etc.) with respect to the main channel (13),and configured for receiving flocculent agent (3) from a feed inlet(19), typically different from the main inlet (11), and has a pluralityof injection outlets (21) disposed about the main outlet (15) forinjection flocculating agent (3) into the fluid flow (5) exiting themain outlet (15), the injection outlets (21) being shaped and sized, andeach having an orifice substantially smaller than that of the feed inlet(19) so as to increase dispersion of the flocculent agent (5) about themain outlet (15) in order to improve mixing of the fluid flow (5) withsaid flocculent agent (3) via an increased exposed surface area of theflocculent agent (3), thus overcoming several of the drawbacks andinconveniences associated with mixing techniques associated with theprior art.

As will be explained in greater detail hereinbelow, it is worthmentioning that, according to the present invention, the injectionoutlets (21) for introducing the flocculating agent (3) into the fluidflow (5) of mature fine tailings (9) in a dispersed manner may bepositioned at different locations, and advantageously, accordinglywithin the injection device (1) and/or pipeline (7) so as to benefitfrom certain dynamic behavior within the fluid flow (5) of the maturefine tailings (9), in order to obtain an improved reaction of theflocculating agent (3) with the mature fine tailings (9).

According to one aspect of the present invention, the injection device(1) is preferably configured so that the main inlet (11) thereof betapered, namely so that fluid flow (5) from the pipeline (7) carryingmature fine tailings (9) entering the injection device (1) goes througha reduced cross-sectional area in order to increase the velocity of thefluid flow (5), and in turn obtain a resulting turbulence within thefluid flow (5) which could advantageously be used when the flocculatingagent (3) is introduced into the fluid flow (5) in a dispersed manner,via the plurality of injection outlets (21), whether directly into sucha turbulent zone of the fluid flow (5), or downstream thereof (and insome cases, even “upstream”), for optimizing the introduction, mixingand/or reaction of the flocculating agent (3) with the mature finetailings (9).

Preferably, and as can be easily understood by a person skilled in theart, although the injection device (1) according to the presentinvention could be used with a main inlet (11) having a cross-sectionalarea which changes abruptly along the channel, for increasing rapidlythe flow velocity of the mature fine tailings (9) traveling therealong,the main inlet (11) for the injection device (1) according to apreferred embodiment of the present invention is preferably graduallytapered so as to progressively increase the flow velocity of the maturefine tailings (9), while attempting to minimize pressure loss of thefluid flow (5) travelling through said transitional segment (55) giventhat any pressure losses throughout the pipeline (7) are cumulative. Forindicative purposes only, and according to a preferred embodiment of thepresent invention, the taper may range anywhere between about 7 degreesand about 90 degrees, depending on the particular application(s) forwhich the present injection device (1) is intended for, and the desiredend result(s), as apparent to a person skilled in the art.

Moreover, it is worth mentioning also that providing a tapered maininlet (11) ensures that less wear will be caused onto the givencomponent of the injection device (1) which provides such a main inlet(11), due to the nature of the mature fine tailings (9) which wouldnormally damage or wear out an internal component of the main inlet (11)in a much faster manner if a change in the cross-sectional area was moreabrupt, as can be easily understood by a person skilled in the art.

Referring more specifically to given preferred embodiments of thepresent invention, as exemplified in FIGS. 1-21, there is shown how theinjection outlets (21) are preferably radially positioned about the mainoutlet (15) of the fluid flow (5) in an equally spaced manner. Morespecifically, according to these particular embodiments, the injectionoutlets (21) are provided about a backing ring (91) at the outermostrear part of the injection device (1). According to these particularembodiments, the injection device (1) preferably comprises eightinjection outlets (21), each being about ⅞ inches in diameter, with acenter point (21 c) for each injection outlet (21) being positionedabout ⅞ inches away from an inner surface (23) of the main channel (13),as better shown in FIGS. 5, 12 and 19. However, it is worth mentioning,as can also be easily understood by a person skilled in the art, that animportant aspect of the present invention resides in the manner in whichthe flocculent agent (3) is introduced or “dispersed” within the fluidflow (5) of the mature fine tailings (9) for increasing a properreaction, thus, the number of injection holes (21), the cross-sectionalconfiguration thereof, the positioning with respect to the main channel(13), and other considerations, may be changed, altered and/or modified,depending on the particular applications for which the injection device(1) is intended for, the type of fluid flow (5) with which it is used,and the desired end results. It is worth mentioning however thatirrespectively of the total number of injection outlets (21), whethertwo, three, four, five, six, seven, eight or more, the total area of theinjection outlets (21) are preferably set to be less than the total flowarea of the feed inlet (19) of flocculent agent (3), thereby ensuringthat the injection outlet (21) is the primary pressure drop point whichjets the solution (i.e flocculating agent (3)) into the MFT, forimproved mixing.

According to one preferred aspect of the present invention, and based oncertain tries having been carried out for optimizing the process, theincreased wetted perimeter of the flocculating agent (3) being injectedout through the injection outlets (21) is preferably about 2.8. However,it is worth mentioning also that such a ratio may vary once again,depending on the particular application(s) for which the presentinjection device (1) is intended for, and the desired end result(s), andthat, in some cases, the exposed area for the polymer when dispersed tomicro drops can be much higher, as can be easily understood by a personskilled in the art (ex. using simulation modeling, etc.). Preferablyalso, and according to another preferred embodiment, the main channel(13) is selected so as to have an internal diameter which is about halfthe size of an internal diameter of the pipeline (7). Indeed, as will bebetter described hereinbelow, the present injection device (1) has beendesigned so as to facilitate assembling and/or manufacturing thereof,with standard or readily available “off-the-shelf” components, whileproviding for a resulting innovative injection device (1) which enablesto introduce the flocculating agent (3) into the fluid flow (5) ofmature fine tailings (9) in an improved manner, for improved mixing endresults.

Thus, it can be appreciated that, for example, an internal diameter ofthe main channel (13) could be about 6 inches, or even 4 inches, for apipeline (7) having an internal diameter of about 12 inches.Furthermore, and as can be easily understood when referring to FIGS.1-21, the feed inlet (19) of the injection device (1) is preferablyprovided with a connecting flange (25) for removably connecting the feedinlet (19) to a source of flocculating agent (3), or any other type ofchemical reactive intended to cooperate with the mature fine tailings(9) circulating through the pipeline (7) for a correspondingflocculation, dewatering, or any other suitable intended purpose, as canbe easily understood by a person skilled in the art.

According to one preferred embodiment, the flocculating agent (3) is aliquid polymer, designed for proper reaction with the mature finetailings (9), but any other suitable substance, agent, chemicalreactive, solution, and/or the like, may be used with the injectiondevice (1), as can be easily understood by a person skilled in the art.It is worth mentioning as is well known in the art that MFT mainlyconsists of water, sand and clay, in which the solids content in the MFTcan range anywhere between about 15-50%. Typical injectors areessentially ineffective on MFT with a solids content greater than 30%,which is about greater or equal to about 1.22 specific gravity. However,the present injection device (1) and corresponding components (injectionoutlets (21), etc.) are designed to work equally well throughout thefull range of MFT solids contents, and this characteristic of theinjection device (1) is an important reason for its design andimplementation into the MFT drying system.

Referring to FIGS. 1-21, there is shown how according to a given aspectof the present invention, the injection device (1) can be assembledusing an inner component (27), and an outer component (37). The innercomponent (27) preferably comprises a cylinder (29) defining the mainchannel (13) along which the fluid flow (5) is allowed or intended totravel, the cylinder (29) having a first end (31) operativelyconnectable to the main inlet (11) and a second end (33) provided with aring (35) operatively connectable to the main outlet (15), the ring (35)being provided with the injection outlets (21).

Referring now to the outer component (37), it preferably comprises asleeve (39) concentrically mounted about the inner component (27), thesleeve (39) having a first end (41) provided with a first flange (43)being removably connectable onto a first section (45) of the pipeline(7), and a second end (47) provided with a second flange (49) beingremovably connectable onto a second section (51) of the pipeline (7) forin-line connection of the injection device (1) with the pipeline (7),the outer component (37) being also provided with the feed inlet (19)projecting outwardly from a peripheral surface (53) of the sleeve (39),as better shown in FIGS. 3, 10 and 17.

As can be easily understood when referring to FIGS. 6, 13 and 20, thecylinder (29) and the sleeve (39) are preferably configured so that thecomplementary conduit (17) is defined thereinbetween when the outercomponent (37) is mounted about the inner component (27), thecomplementary conduit (17) being in fluid communication between the feedinlet (19) and the injection outlets (21) provided on the ring (35) ofthe inner component (27) so that flocculating agent (3) introduced intothe complementary conduit (17) via the feed inlet (19) is injected outthe injection outlets (21) of the inner component (27) so as to increasedispersion of the flocculating agent (3) within the fluid flow (5), ascan be easily understood when referring to FIGS. 7, 14 and 21.

Similarly to what was described earlier, the first end (31) of thecylinder (29) of the inner component (27) is preferably tapered, in agradual manner. Advantageously, and preferably also, the outer component(37) consists of a standard fitting, for facilitating procurement andassembling of the components of the injection device (1). For example,the first and second ends (31,33) of the cylinder (29) can respectivelybe welded onto the first and second ends (41,47) of the sleeve (39), ascan be easily understood when referring to FIGS. 6, 13 and 20, althoughother suitable ways of assembling, affixing and/or securing the variouscomponents of the injection device (1) are also intended with thepresent invention, as can be easily understood by a person skilled inthe art.

Although different variations of possible in-line injection devices (1)have been explained and illustrated in the present description, it isworth mentioning that an important aspect of the present inventionresides in the provision of a new method for in-line injection offlocculating agent (3) into a pipeline (7) of mature fine tailings (9)in order to promote flocculation of said mature fine tailings (9) andobtain other resulting advantages, as can be easily understood by aperson skilled in the art. The method preferably comprises the steps of:a) providing a fluid flow (5) of mature fine tailings (9) to be treatedalong a given channel fluidly connected to the pipeline (7); b)providing a source of flocculating agent (3); and c) introducingflocculating agent (3) inside the fluid flow (5) of mature fine tailings(9) via a plurality of injection outlets (21) for injecting theflocculating agent (3) into the fluid flow (5) in a dispersed manner soas to increase an exposed surface area of the injected flocculatingagent (3) and thus increase a corresponding reaction with the maturefine tailings (9), for an improved flocculation of the mature finetailings (9), and/or other resulting advantages. As apparent to a personskilled in the art, the manners in which this method and correspondinginjection device (1) could be used are various.

For example, step c) could comprise the step of i) creating a zone ofturbulence within the fluid flow (5) of mature fine tailings (9); andii) injecting flocculating agent (3) in a dispersed manner via theplurality of injection outlets (21) within said zone of turbulence formixing the flocculating agent (3) with the mature fine tailings (9) andfurther promoting flocculation of the mature fine tailings (9).

Step a) of the present invention could also comprise the step of iii)reducing the cross-sectional area of the channel along a giventransitional segment (55) of the channel for increasing the flowvelocity of the mature fine tailings (9) travelling through saidtransitional segment (55), and in turn increasing a turbulence of thefluid flow (5) exiting form the transitional segment (55), as can beeasily understood when referring to FIGS. 7, 14 and 21.

Step a) of the present invention could also comprise the step ofgradually reducing the cross-sectional area of the channel along a givenslope, which in some of the embodiments illustrated in the accompanyingdrawings, preferably has a ratio of about 7 to 1, as better shown inFIG. 33 for example, so as to namely, and as previously explained,prevent a pressure loss of the fluid flow (5) travelling through saidtransitional segment (55).

It is worth mentioning also that step a) of the present invention couldalso comprise the step of iv) rapidly increasing the cross-sectionalarea of the channel along a given interface segment (57) of the channelfor abruptly altering the flow velocity of the mature fine tailings (9)travelling through said interface segment (57) of the channel, in orderto create a turbulent zone of fluid flow (5) adjacent to said interfacesegment (57). As can be easily understood by a person skilled in theart, this abrupt change in cross-sectional area of the fluid flow (5) isdone when the fluid flow (5) exits the main channel (13) of theinjection device (1) and flows back into the pipeline (7) at the secondsection (51) thereof, as schematically represented in FIGS. 7, 14 and21.

According to one aspect of the present invention, step c) of the methodcould comprise the step of positioning the injection outlets (21) aboutthe main segment (59) of the channel so that the flocculating agent (3)is injected radially towards a longitudinal axis (61) of the fluid flow(5), as exemplified in FIG. 38.

Alternatively, or additionally, step c) could also comprise the step ofpositioning the injection outlets (21) about an interface segment (57)of the channel so that the flocculating agent (3) is injected in adirection substantially parallel to a longitudinal axis (61) of thefluid flow (5), as exemplified in FIGS. 7, 14 and 21.

Preferably, and for improved reactive purposes, the flocculating agent(3) is injected through the plurality of injection outlets (21) into aturbulent zone created and defined adjacent to said interface segment(57), so that the flocculating agent (3) may react advantageously due toits dispersion via a plurality of injection outlets (21), which providefor an increased exposed surface area, and thus resulting improvedreaction, in addition to being injected in a zone of turbulence whichcould also further add to the improved reaction with the mature finetailings (9).

According to another aspect of the present invention, and as can beeasily understood when referring to FIGS. 24-38, there is also provideda kit for assembling an injection device (1) for in-line injection offlocculating agent (3) into a fluid flow (5) of a pipeline (7) of maturefine tailings (9). The kit may comprise a tee joint (63) (or simplyt-joint (63)), a first flange (71), a second flange (73), a third flange(75), a reducer (77) and an inner pipe (83).

Preferably, and as better shown in FIGS. 24-27, the t-joint (63) hasfirst, second and third sections (65,67,69), each section (65,67,69)being provided with the corresponding orifice (65 a,67 a,69 a) beingfluidly connected to each other. The first flange (71) is preferablymountable about the first section (65) of the t-joint (63), and isconfigured for mounting the assembled injection device (1) onto a firstsection (45) of the pipeline (7), as exemplified in FIGS. 22 and 23. Thesecond flange (73) is preferably mountable about the second section (67)of the t-joint (63), and is configured for mounting the assembledinjection device (1) onto a second section (51) of the pipeline (7). Thethird flange (75) is preferably mountable about the third section (69)of the t-joint (63), and is configured for connecting the assembledinjection device (1) to a source of flocculating agent (3), asrepresented schematically in FIG. 23.

The reducer (77) of the kit is preferably mountable onto the firstsection (65) of the t-joint (63) so as to be positioned inside thet-joint (63), as better shown in FIG. 27, and the reducer (77) has aninlet (79) and an outlet (81), the inlet (79) of the reducer (77) beingconcentrically mountable about the orifice (65 a) of the first section(65) of the t-joint (63), the cross-sectional area of the reducer (77)being reduced from its inlet (79) to its outlet (81), for obtainingcorresponding resulting advantages, as briefly described hereinabove.

Referring now to FIG. 38, and as can be easily understood, the innerpipe (83) is preferably mountable onto the second section (67) of thet-joint (63) so as to be positioned inside the t-joint (63), the innerpipe (83) having an inlet (85) and an outlet (87), the inlet (85) of theinner pipe (83) being connectable to the outlet (81) of the reducer(77), the outlet (87) of the inner pipe (83) being concentricallymountable about the orifice (67 a) of the second section (67) of thet-joint (63), the inner pipe (83) being cooperable with the secondsection (67) of the t-joint (63) for defining a plurality of injectionoutlets (21) about the outlet (87) of the inner pipe (83) so thatflocculating agent (3) coming from the third section (69) of the t-joint(63) be injected in a dispersed manner through said injection outlets(21) and into the fluid flow (5) of mature fine tailings (9) travellingthrough the reducer (77) and the inner pipe (83). As previouslyexplained, and according to a preferred aspect of the present invention,the injection outlets (21) may be provided about different suitablelocations within the injection device (1), whether it be directly aboutthe inner pipe (83), or provided about a corresponding ring (35).

According to a given preferred embodiment, the second section (67) ofthe t-joint (63) preferably includes an outer pipe (89) positionableconcentrically about the inner pipe (83) for defining a conduit (17)thereinbetween destined to receive the flocculated agent (3), as can beeasily understood when referring to FIGS. 33 and 38. Preferably also,the second flange (73) is mountable onto the outer pipe (89), and thekit further comprises a backing ring (35,91) mountable between the innerpipe (83) and the outer pipe (89). The backing ring (91) may be providedwith injection outlets (21) for receiving flocculating agent (3) fromthe second section (67) of the t-joint (63), and for injecting theflocculent agent (3) into the fluid flow (5) in a dispersed manner, ascan be easily understood when referring to the preferred embodiments ofthe present invention illustrated in FIGS. 1-21.

According to another aspect, the kit may also comprise a lap ring (93)mountable onto the second flange (73), as well as a nut (95) mountableonto the second flange (73), and as can be easily understood whenreferring to FIGS. 27, 33 and 38, the components of the kit operativelysecured onto one another in a suitable manner, and preferably, by anappropriate assembling or connecting method, such by welding, forexample.

It is worth mentioning that various other suitable injection devices (1)may be provided for carrying out the injection method according to thepresent invention. For example, when referring to FIGS. 39-43, there isshown how according to a given preferred embodiment, the injectiondevice (1) according to the present invention may also be provided in aform of an injection device (1) for use with a lateral pipe fitting (97)of a pipeline (7) of mature fine tailings (9), the lateral pipe fitting(97) having a substantially y-joint arrangement including a main line(99) along which a fluid flow (5) of mature fine tailings (9) isintended to travel, and a corresponding branch line (101). The injectiondevice (1) may comprise an abutment flange (103) for abutting against adistal end (105) of the branch line (101). The injection device (1) mayalso comprise a supporting body (107) projecting from the abutmentflange (103) inwardly towards the main line (99), the supporting body(107) having an internal conduit (109) for conveying flocculent agent(3) to be introduced into the fluid flow (5) via a corresponding distalextremity (111) (or “end portion”) intersecting the fluid flow (5) ofmature fine tailings (9). The injection device (1) also preferablycomprises a plurality of injection outlets (21) provided on the distalextremity (111) (i.e. “end portion”) of the supporting body (107), andthrough which flocculent agent (3) is injected, the injection outlets(21) being shaped and sized, and each having an orifice substantiallysmaller than that of the internal conduit (109) so as to increasedispersion of the flocculating agent (3) about the injection outlets(21) in order to improve mixing of the fluid flow (5) with saidflocculating agent (3) via an increased exposed surface area of theflocculating agent (3) provided by the plurality of injection outlets(21).

According to a first preferred embodiment, as better shown in FIG. 39,the supporting body (107) of the injection device (1) is configured sothat its distal extremity (111) is positioned about a main longitudinalaxis (61) of the fluid flow (5), and so that injection outlets (21) arepositioned substantially below said longitudinal axis (61).

According to another preferred embodiment, as better shown in FIG. 40,the supporting body (107) of the injection device (1) is configured sothat its distal extremity (111) is positioned above a main longitudinalaxis (61) of the fluid flow (5), and so that injection outlets (21) aresubstantially positioned about said longitudinal axis (61).

The supporting body (107) may simply be a cylinder or a pipe, andaccording to a given embodiment, as better shown in FIGS. 42 and 43, theinjection outlets (21) are disposed about the supporting body (107)along four rows of injection outlets (21), with about 30 degrees ofradial separation between each row of injection outlets (21), and mostof the injection outlets (21) being about ⅜ inches in diameter.Preferably also, the internal conduit (109) of the supporting body (107)is about ¾ inches in diameter. Once again, it is worth mentioning, ascan also be easily understood by a person skilled in the art, that animportant aspect of the present invention resides in the manner in whichthe flocculent agent (3) is introduced or “dispersed” within the fluidflow (5) of the mature fine tailings (9) for increasing a properreaction, thus, the number of injection holes (21), the cross-sectionalconfiguration thereof, the number of rows of said injections holes (21),the positioning with respect to the main channel (13) or internalconduit (109), and other considerations, may be changed, altered and/ormodified, depending on the particular applications for which theinjection device (1) is intended for, the type of fluid flow (5) withwhich it is used, and the desired end results.

The supporting body (107) is preferably provided with a stabilizer (113)for resting against an inner wall of the branch line (101), whichenables namely to maintain the distal extremity (111) of the injectiondevice (1) substantially fixed with respect to the fluid flow (5),thereby minimizing vibrations to said distal extremity (111), etc., ascan be easily understood by a person skilled in the art.

Finally, and according to the present invention, the injecting device(1) and corresponding parts are preferably made of substantially rigidmaterials, such as metallic materials (stainless steel, etc.), hardenedpolymers, composite materials, and/or the like, whereas other componentsthereof according to the present invention, in order to achieve theresulting advantages briefly discussed herein, may preferably be made ofa suitably malleable and resilient material, such as a polymericmaterial (plastic, rubber, etc.), and/or the like, depending on theparticular applications for which the injecting device (1) and resultingpipeline (1) or closed circuit are intended for and the differentparameters in cause, as apparent to a person skilled in the art.

Furthermore, the present invention is a substantial improvement over theprior art in that, by virtue of its design and components, the device(1) is simple and easy to use, as well as is simple and easy tomanufacture and/or assemble, and provides for a much more efficient andcost effective manner of processing MFT.

Indeed, as may now be better appreciated, the present invention issubstantially advantageous over conventional techniques in that itallows for a much faster and more efficient mixing of liquid polymerwith the mature fine tailings (MFT), namely due to the fact that theflocculating agent (for example, liquid polymer) is introduced into thefluid flow of mature fine tailings in a dispersed manner via a pluralityof injection outlets. This enables namely a lower polymer usage for thesame quantity of MFT as compared to an un-optimized design. Moreover,this enables for increased process efficiency.

The present invention is also advantageous in that it allows for verylow maintenance on a device and fabrication can be completed in-house,with straightforward “off-the-shelf” components, as briefly explainedhereinabove.

As may also now be better appreciated, the solution proposed with thepresent invention is also advantageous in that it introduces liquidpolymer into the MFT at a higher velocity through multiple openings,thus increasing the exposed surface area of the liquid polymer. Incontrast, conventional techniques minimize exposed surface area of thepolymer which leaves a large amount of polymer unmixed, with associateddrawbacks and inconveniences. It is worth mentioning also that accordingto the present invention, the design of the injection spool alsopromotes a turbulent zone near the point of injection which aids inrapidly mixing the dispersed polymer. Thus, there is an increasedcontact area between the polymer and the MFT at the injection point.Moreover, and as explained earlier, the design of the injector spoolpromotes a turbulent zone at the area of injection which promotes rapidmixing of MFT and polymer. Typically, with an inefficient injectiondevice, excess polymer is added to compensate for the poor injection,whereas the present new and innovative design enables to make up for theinefficiency and polymer usage can be minimized.

Indeed, an important aspect of the present invention resides in thatinstead of polymer injection into the MFT stream via a large opening, asis normally done in the prior art, polymer injection is done throughmultiple holes of smaller diameter achieving the same or even greateroverall injection velocity but significantly increasing the exposedpolymer surface area, for an improved reactive process and improved endresults.

As previously explained, and according to one preferred embodiment ofthe present invention, the present injection device reduces the 12 inchMFT flow down to a 6 inch flow through a concentric reducer. The flow isthen dramatically expanded from 6 inches back to 12 inches creating aturbulent zone. This zone is the location where preferably polymerinjection holes are provided, for the injection of the liquid polymer.This provides adequate contact area for the polymer while also providingextra mixing of the two fluids. In the present case, mixing takes placedirectly at the injection point which is positioned and placedaccordingly, for optimal results. Because the injection of the polymeris optimized, the mixture subsequently enters the drying cell with thegreatest potential for immediate water release and optimal drying times,two process requirements for MFT drying.

It is worth mentioning also that fabrication of the present injectiondevice (1) is fairly simple to carry out, in that, according to apreferred embodiment, it may simply involve a standard t-fitting withstandard steel parts inside of minimal complexity. Therefore, it caneconomically be fabricated, with relatively readily availableoff-the-shelf components. Furthermore, the present invention is alsoadvantageous in that the maintenance of the injection device (1) isfairly minimal as the component is essentially run to failure withsurface wear being the failure mechanism. Because the service is MFT,the wear rates are much lower than with coarse tailings.

Various other variations or alternatives of the present invention couldbe made, as apparent to a person skilled in the art. For example, it hasbeen explained that once the injection location is chosen, the device(1) can be installed in-line with standard flange connections. This istypically done on a 12 inch MFT pipeline. The polymer inlet is thustypically 8 inch and can also be connected to the device via a standard8 inch flange inlet. However, it is worth mentioning that various otherbarometers or design variables could be considered for the presentinvention in that for example, one of them could be the reduction of theinternal pipe from 6 inch to 4 inch. Indeed, the subsequent turbulentzone becomes larger and it is thought that this can aid in mixing duringtimes where the feed density dictates such a change. It is also worthmentioning that standard flange connections provide for easyinstallation, and that for particular applications, expansion from 6inch internal diameter to 12 inch provides a turbulent zone wherebyextra mixing is induced into the injection area.

Moreover, it is worth mentioning also, that although the main outlet(15) of the present injection device (1) has been exemplified in theaccompanying drawings as being substantially “vertical”, such an outlet(15) may deviate from a vertical plane, at a given angle, for example,within a range of about 10 degrees relative to the horizontal up tovertical. Indeed, a person skilled in the art may appreciate that whilemechanical construction of the vertical unit is easier, an appropriateangle of the outlet (15) promotes some recovery of the pressure whilemixing the fluids. Therefore, one can view the injection orifices (21)shown in FIG. 33 as being a 0-degree case. Furthermore, a person skilledin the art will also understand that the fact of having sharp-edged orrounded-edged injection orifices (21) will affect the flow rate throughthe nozzle. Sharp edges are easiest to drill, while tapered or roundededges provide better flow capacity. Thus, in addition to the variouschanges that could be made to the present injection device (1), not onlythe shape and the positioning of the injection outlets (21) can bevaried depending on different application(s) for which the injectiondevice (1) is intended for, and the desired end result(s), but it isimportant to note also that the injection outlets (21) are notnecessarily limited to “round” configurations or cross-sections,although they are easier to manufacture by simple drilling, punching,and the like, and that these very same injection outlets (21) ororifices can be made to take on various other suitable geometricconfigurations, and cross-sectional shapes, such as “star-like”configurations, for example, so as to further increase the exposedsurface area (or “wetted perimeter”) of the flocculating agent (3)introduced into the fluid flow (5) by means of said injection outlets(21), as also apparent to a person skilled in the art.

Of course, numerous other modifications could be made to theabove-described embodiments without departing from the scope of theinvention, as defined in the appended claims.

1-42. (canceled)
 43. An in-line tailings flocculation system,comprising: a tailings feed pipeline configured to provide a flow oftailings and having an upstream end and a downstream end; an in-lineflocculant injector for injecting a flocculation liquid containing aflocculating agent into the tailings, the in-line flocculant injectorcomprising: a sleeve comprising: a first end configured to be coupled tothe downstream end of the tailings feed pipeline; a second endconfigured opposite the first end; and a side inlet in between the firstand second ends and configured to receive a flow of the flocculationliquid; a tailings conduit defining a fluid passage therethrough andbeing mounted within the sleeve, the tailings conduit comprising: afrusto-conical segment that tapers inwardly in a downstream direction ofthe flow of tailings, the frusto-conical segment comprising: an upstreamportion mounted to an inner surface of the first end of the sleeve andconfigured to receive the flow of tailings from the tailings feedpipeline; and a downstream portion located within the sleeve; acylindrical segment having a wall thickness and comprising: an upstreamsection coupled to the downstream portion of the frusto-conical segment;a downstream section defining a tailings outlet; and a plurality ofinjection outlets through the wall thickness; a backing ring mountedabout the tailings outlet of the cylindrical segment in between thecylindrical segment and the sleeve, such that the backing ring, thetailings conduit and the sleeve define therebetween an annularflocculant conduit that receives the flow of the flocculation liquidfrom the side inlet of the sleeve, the annular flocculant conduit beingin fluid communication with the fluid passage via the injection outlets,such that the flocculation liquid is capable of flowing from the sideinlet, through the annular flocculant conduit and out of injectionoutlets into the flow of the tailings in the fluid passage to form aflocculation material which is expelled via the tailings outlet; adownstream pipeline coupled to the second end of the sleeve being influid communication with the fluid passage of the tailings conduit so asto receive the flocculation material.
 44. The in-line tailingsflocculation system of claim 43, wherein the plurality of injectionoutlets comprises injection outlets that are arranged circumferentiallyabout the cylindrical segment of the tailings conduit.
 45. The in-linetailings flocculation system of claim 44, wherein the plurality ofinjection outlets comprises at least one opposed pair of injectionoutlets that are arranged on opposite lateral sides of the cylindricalsegment.
 46. The in-line tailings flocculation system of claim 44,wherein the plurality of injection outlets comprises at least oneperpendicular pair of injection outlets that are arranged at ninetydegrees with respect to each other.
 47. The in-line tailingsflocculation system of claim 43, wherein the injection outlets each havea circular cross-section.
 48. The in-line tailings flocculation systemof claim 43, wherein the frusto-conical segment and the cylindricalsegment of the tailings conduit join at a connection point that isdownstream of a centerline axis of the side inlet.
 49. The in-linetailings flocculation system of claim 43, wherein the second end of thesleeve comprises a flange extending outward and configured to be coupledto a corresponding flange of the downstream pipeline to secure thesleeve thereto.
 50. The in-line tailings flocculation system of claim49, further comprising opposed first and second mounting components oneither side of the flange to prevent axial movement of the flange. 51.The in-line flocculation system of claim 50, wherein the first mountingcomponent comprises a lap ring on a downstream side of the flange and anut on an upstream side of the flange.
 52. The in-line flocculationsystem of claim 43, wherein the upstream portion of the frusto-conicalsegment is connected to an inner surface of the first end of the sleeveby a circumferential weld.
 53. The in-line flocculation system of claim43, wherein the downstream portion of the frusto-conical segment isconnected to the cylindrical segment by a circumferential weld.
 54. Thein-line flocculation system of claim 43, wherein the injection outletseach have a cross-sectional size that is substantially smaller than across-section of the cylindrical segment.
 55. The in-line flocculationsystem of claim 43, wherein the injection outlets each have across-sectional size that is substantially smaller than a cross-sectionof the side inlet.
 56. An in-line flocculant injector for injecting aflocculation liquid containing a flocculating agent into a flow oftailings, comprising: a sleeve comprising: a first end configured toreceive the flow of tailings; a second end downstream from the firstend; and a side inlet in between the first and second ends andconfigured to receive a flow of the flocculation liquid; a tailingsconduit defining a fluid passage therethrough and being mounted withinthe sleeve, the tailings conduit comprising: a reducer that tapersinwardly in a downstream direction of the flow of tailings and beingmounted within the sleeve; an injection segment having a wall thicknessand comprising: an upstream section coupled to a downstream portion ofthe reducer; a downstream section defining a tailings outlet; and aplurality of injection outlets through the wall thickness; wherein thetailings conduit and the sleeve define therebetween a flocculant conduitthat receives the flow of flocculation liquid from the side inlet of thesleeve, the flocculant conduit being in fluid communication with thefluid passage via the injection outlets, such that the flocculationliquid is capable of flowing from the side inlet, through the flocculantconduit and out of injection outlets into the flow of the tailings inthe fluid passage to form a flocculation material which is expelled viathe tailings outlet.
 57. The in-line flocculant injector of claim 56,wherein the reducer has a frusto-conical shape and the injection segmenthas a cylindrical shape.
 58. The in-line flocculant injector of claim56, further comprising a backing ring secured in between the second endof the sleeve and the downstream section of the injection segment, andthe backing ring defines an end surface of the flocculant conduit. 59.The in-line flocculant injector of claim 58, wherein the flocculantconduit has an annular cross-sectional shape.
 60. The in-line flocculantinjector of claim 56, wherein the injection outlets each have across-sectional size that is substantially smaller than a cross-sectionof the cylindrical segment.
 61. The in-line flocculant injector of claim60, wherein the plurality of injection outlets comprises at least fourinjection outlets that are equally spaced apart about a circumference ofthe injection segment of the tailings conduit.
 62. The in-lineflocculant injector stem of claim 56, wherein the tailings conduit iscentered within the sleeve along a longitudinal axis thereof thatextends between the first and second ends.
 63. The in-line flocculantinjector of claim 56, wherein the reducer comprises side walls thatdefine an acute angle with respect to a longitudinal axis extendingalong a centerline of the reducer.
 64. The in-line flocculant injectorof claim 56, wherein the tailings conduit is defined by side walls thatdefine inner and outer continuous flat surfaces but for the injectionoutlets.
 65. The in-line flocculant injector of claim 56, wherein thereducer is longer than the injection segment.
 66. An in-line flocculantinjector for injecting a flocculation liquid containing a flocculatingagent into a flow of tailings, comprising: a sleeve comprising: a firstend configured to receive the flow of tailings; a second end downstreamfrom the first end; and a side inlet in between the first and secondends and configured to receive a flow of the flocculation liquid; atailings conduit defining a fluid passage therethrough and being mountedwithin the sleeve, the tailings conduit comprising: a reducer mountedwithin the sleeve and configured to receive and accelerate the flow oftailings to provide a flowrate increased tailing flow; an injectionsegment having a wall thickness and comprising: an upstream sectioncoupled to the reducer to receive the flowrate increased tailing flowtherefrom; a downstream section defining a tailings outlet; and aplurality of injection outlets through the wall thickness; wherein thetailings conduit and the sleeve define therebetween a flocculant conduitthat receives the flow of flocculation liquid from the side inlet of thesleeve, the flocculant conduit being in fluid communication with thefluid passage via the injection outlets, such that the flocculationliquid is capable of flowing from the side inlet, through the flocculantconduit and out of injection outlets into the flowrate increased tailingflow to form a flocculation material which is expelled via the tailingsoutlet.
 67. The in-line flocculant injector of claim 66, wherein thereducer comprises side walls that taper inwardly in a downstreamdirection.